A new cherry [Prunus avium] rootstock variety "Chishimadai 1 Go"

Summary A new cherry rootstock variety "Chishimadai 1 go" was developed by the Hokkaido Central Agricultural Experiment Station and the Hokkaido Donan Agricultural Experiment Station. It was recommended by Hokkaido Government in 2002 and now its patent has been: applied to the ministry of Agriculture, Forestry and Fisheries. It was selected from the 114 seedlings of "Chishimazakura" (Prunus. nipponica Matsum var, kurilensis Wilson) grown in Hokkaido natively. "Chishimazakura" is cold resistant and its tree size is small. Grafting many sweet cherry cultivars on "Chishimadai 1 go" is so successful that survived rate is high. Sweet cherry cultivars on "Chishimadai 1 go" show higher cold resistance compared with that on "Aobazakura" (P. lannesial4a forma mutiplex Miyos) which is used as a cherry rootstock widely. Sweet cherry cultivars on "Aobazakura" are suffered from winter injury frequently in Hokkaido. "Nanyo" leading cherry cultivar in Hokkaido, on "Chishimadai 1 go" is much smaller In tree size than that on "Colt" which is also used as a cherry rootstock wldely. Though "Nanyo" tree on "Colt" is vigorous, its tree size is too large. Consequently picking is labourous, structuring for preventing fruit cracking by rain is not easy. Grafting union between "Nanyo" and "Chishimadai 1 go" is much better than that between "Nanyo" and "Aobazakura". "Aobazakura" don't show good grafting compatibility with sweet cherry cultivars, so cherry trees on "Aobazakura" frequently fall down. Root suckers from "Chishimadai 1 go" are much rare, compared with "Aobazakura" and "Colt". Vegetative propagation of "Chishimadai 1 go" is not so easy as Aobazakura" and "Colt". But vegetative propagation is capable by two methods. First method is interstock grafting on cuttings of "Aobazakura" "Chishimadai 1 go" grafted on "Aobazakura" grows vigorously, reaches to rootstock size in about 2 years after grafting. Second method is soft wood cutting. 80% cuttings survived by soft cutting method. Rooted cuttings grow slowly, so it takes about 4 years to rootstock size.